iOS中正确的截屏姿势

0xBBC · 2014 年12 月 21 日 06:43

依旧是从博客搬运过来的，博客原文。
论坛这边因为没开放HTML标签，所以会失去代码高亮。
如果更习惯看有高亮的代码的话（比如我），也可以直接去看博客原文。
如果有其他方法，欢迎补充～

[list]
*]第一种
这是iOS 3时代开始就被使用的方法，它被废止于iOS 7。iOS的私有方法，效率很高。#import <QuartzCore/QuartzCore.h>
extern “C” CGImageRef UIGetScreenImage();
UIImage * screenshot(void) NS_DEPRECATED_IOS(3_0,7_0);
UIImage * screenshot(){
UIImage *image = [UIImage imageWithCGImage:UIGetScreenImage()];
return image;
}[list]
*]第二种
[/list]这是在比较常见的截图方法，不过不支持Retina屏幕。UIImage * screenshot(UIView *);
UIImage * screenshot(UIView *view){
UIGraphicsBeginImageContext(view.frame.size);
[view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}[list]
*]第三种
[/list]从iPhone 4、iPod Touch 4开始，Apple逐渐采用Retina屏幕，于是在iOS 4的SDK中我们有了，上面的截图方法也自然变成了这样。UIImage * screenshot(UIView *) NS_AVAILABLE_IOS(4_0);
UIImage * screenshot(UIView *view){
if(UIGraphicsBeginImageContextWithOptions != NULL)
{
UIGraphicsBeginImageContextWithOptions(view.frame.size, NO, 0.0);
} else {
UIGraphicsBeginImageContext(view.frame.size);
}
[view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}[list]
*]第四种
[/list]或许你会说有时Hook的是一个按钮的方法，用第三个方法的话，根本找不到view来传值，不过还好，iOS 7又提供了一些UIScreen的API。UIImage * screenshot(void) NS_AVAILABLE_IOS(7_0);UIImage * screenshot(){
UIView * view = [UIScreen mainScreen] snapshotViewAfterScreenUpdates:YES];
if(UIGraphicsBeginImageContextWithOptions != NULL)
{
UIGraphicsBeginImageContextWithOptions(view.frame.size, NO, 0.0);
} else {
UIGraphicsBeginImageContext(view.frame.size);
}
[view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}[list]
*]第五种
[/list]@interface SBScreenShotter : NSObject

(id)sharedInstance;

(void)saveScreenshot:(_Bool)arg1;
@end然后直接[SBScreenShotter sharedInstance] saveScreenshot:YES];一道白光之后，咱们就模拟了用户截屏的动作，不过这个方法在只需要截屏时比较好，如果要对屏幕录像（其实就是不断截图）的话，那不得闪瞎了。。而且我们也拿不到UIImage的实例去拼成一个视频呀。即使通过Hook别的类拿到UIImage的实例，这个私有API的效率大概也是达不到30FPS的视频要求的。那么现在我们有5种方法了，第一种是私有API，私有API通常效率和质量都比Documented API的好，可是它在iOS 7以后就被废除了啊，就没有别的了吗？答案当然是————有的！用Private Framework来完成这项任务！直接走底层拿屏幕的缓冲数据，然后生成UIImage的实例。[list]
]第六种
[/list]#import <IOMobileFrameBuffer.h>
#import <UIKit/UIKit.h>
#import <QuartzCore/QuartzCore.h>
#import <IOKit/IOKit.h>
#import <IOSurface/IOSurface.h>extern “C” IOReturn IOSurfaceLock(IOSurfaceRef buffer, uint32_t options, uint32_t seed);
extern “C” IOReturn IOSurfaceUnlock(IOSurfaceRef buffer, uint32_t options, uint32_t seed);
extern “C” size_t IOSurfaceGetWidth(IOSurfaceRef buffer);
extern “C” size_t IOSurfaceGetHeight(IOSurfaceRef buffer);
extern “C” IOSurfaceRef IOSurfaceCreate(CFDictionaryRef properties);
extern “C” void IOSurfaceGetBaseAddress(IOSurfaceRef buffer);
extern “C” size_t IOSurfaceGetBytesPerRow(IOSurfaceRef buffer);extern const CFStringRef kIOSurfaceAllocSize;
extern const CFStringRef kIOSurfaceWidth;
extern const CFStringRef kIOSurfaceHeight;
extern const CFStringRef kIOSurfaceIsGlobal;
extern const CFStringRef kIOSurfaceBytesPerRow;
extern const CFStringRef kIOSurfaceBytesPerElement;
extern const CFStringRef kIOSurfacePixelFormat;enum
{
kIOSurfaceLockReadOnly =0x00000001,
kIOSurfaceLockAvoidSync =0x00000002
};UIImage * screenshot(void);UIImage * screenshot(){
IOMobileFramebufferConnection connect;
kern_return_t result;
CoreSurfaceBufferRef screenSurface = NULL;
io_service_t framebufferService = IOServiceGetMatchingService(kIOMasterPortDefault, IOServiceMatching(“AppleH1CLCD”));
if(!framebufferService)
framebufferService = IOServiceGetMatchingService(kIOMasterPortDefault, IOServiceMatching(“AppleM2CLCD”));
if(!framebufferService)
framebufferService = IOServiceGetMatchingService(kIOMasterPortDefault, IOServiceMatching(“AppleCLCD”));result = IOMobileFramebufferOpen(framebufferService, mach_task_self(), 0, &connect);
result = IOMobileFramebufferGetLayerDefaultSurface(connect, 0, &screenSurface); uint32_t aseed;
IOSurfaceLock((IOSurfaceRef)screenSurface, 0x00000001, &aseed);
size_t width = IOSurfaceGetWidth((IOSurfaceRef)screenSurface); size_t height = IOSurfaceGetHeight((IOSurfaceRef)screenSurface);
CFMutableDictionaryRef dict;
size_t pitch = width4, size = widthheight4; int bPE=4; char pixelFormat[4] = {‘A’,‘R’,‘G’,‘B’};
dict = CFDictionaryCreateMutable(kCFAllocatorDefault, 0, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
CFDictionarySetValue(dict, kIOSurfaceIsGlobal, kCFBooleanTrue);
CFDictionarySetValue(dict, kIOSurfaceBytesPerRow, CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &pitch));
CFDictionarySetValue(dict, kIOSurfaceBytesPerElement, CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &bPE));
CFDictionarySetValue(dict, kIOSurfaceWidth, CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &width));
CFDictionarySetValue(dict, kIOSurfaceHeight, CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &height));
CFDictionarySetValue(dict, kIOSurfacePixelFormat, CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, pixelFormat));
CFDictionarySetValue(dict, kIOSurfaceAllocSize, CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &size)); IOSurfaceRef destSurf = IOSurfaceCreate(dict);
IOSurfaceAcceleratorRef outAcc;
IOSurfaceAcceleratorCreate(NULL, 0, &outAcc); IOSurfaceAcceleratorTransferSurface(outAcc, (IOSurfaceRef)screenSurface, destSurf, dict, NULL);
IOSurfaceUnlock((IOSurfaceRef)screenSurface, kIOSurfaceLockReadOnly, &aseed);
CFRelease(outAcc); CGDataProviderRef provider = CGDataProviderCreateWithData(NULL, IOSurfaceGetBaseAddress(destSurf), (width * height * 4), NULL); CGImageRef cgImage = CGImageCreate(width, height, 8,
84, IOSurfaceGetBytesPerRow(destSurf),
CGColorSpaceCreateDeviceRGB(), kCGImageAlphaNoneSkipFirst|kCGBitmapByteOrder32Little, provider, NULL, YES, kCGRenderingIntentDefault); UIImage *image = [UIImage imageWithCGImage:cgImage];
return image;
}

[/list]
需要注意的是，第五种方法需要修改一下IOMobileFramebuffer的头文件。typedef void * IOMobileFramebufferConnection;
修改好的头文件。headers.zip (61.8 KB)解压后放在Project的根目录下。如果你使用的是theos的话，记得在Makefile里写上，YOUR_TWEAK_NAME_PRIVATE_FRAMEWORKS = IOSurface IOKit IOMobileFramebuffer**YOUR_TWEAK_NAME_CFLAGS = -I./headers/ -I./headers/IOSurface如果是XCode上的Logos Tweak的话，在Build Settings → Search Paths → Header Search Paths里面添加一项：$(PROJECT_DIR)/YOUR_PROJECT_NAME/headers, 搜索方式为recursive. 最后在Build Phases里Link上IOSurface IOKit IOMobileFramebuffer这三个私有Framework。

0xBBC · 2014 年12 月 21 日 06:47

Discuz的编辑器略坑呀。。
转代码格式之后直接显示HTML代码了。。。

iOSRer · 2014 年12 月 21 日 06:47

多谢楼主分享，不过看到帖子题目（姿势），再看到内容，我才知道我想错了。

FF1990 · 2014 年12 月 26 日 12:53

好像游戏里面不能截图
楼主有办法在游戏里截图吗

lok_ios · 2014 年12 月 29 日 05:30

多谢楼主分享，如果是连续截取的话，那种效率好点，比如內存的使用.

wingbywings · 2015 年1 月 7 日 09:22

楼主，第4种方法在IOS8里用你的代码是空白的图片呢。
以下代码会返回正常的

 
    UIView *snapshot = [UIScreen mainScreen] snapshotViewAfterScreenUpdates:YES];
    CGSize outputSize = CGSizeMake([UIScreen mainScreen].bounds.size.width, [UIScreen mainScreen].bounds.size.height);
    UIGraphicsBeginImageContextWithOptions(outputSize, NO, 0);
    [snapshot drawViewHierarchyInRect:CGRectMake(0.0, 0.0, outputSize.width, outputSize.height) afterScreenUpdates:YES];   //貌似IOS8要用这个方法
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

hole · 2015 年1 月 14 日 02:38

在游戏里面截图可以呀，写一个tweak然后调用截图就可以了，只不过只能截最上层的！